An interdomain linker increases the thermostability and decreases the calcium affinity of the calmodulin N-domain

Brenda R Sorensen; Laurel A Faga; Rainbo Hultman; Madeline A Shea

doi:10.1021/bi011718+

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An interdomain linker increases the thermostability and decreases the calcium affinity of the calmodulin N-domain

Journal article

Peer reviewed

An interdomain linker increases the thermostability and decreases the calcium affinity of the calmodulin N-domain

Brenda R Sorensen, Laurel A Faga, Rainbo Hultman and Madeline A Shea

Biochemistry (Easton), Vol.41(1), pp.15-20

01/08/2002

DOI: 10.1021/bi011718+

PMID: 11771998

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Abstract

A hydrophobic core is a widely accepted determinant of protein stability. However, regulatory proteins undergoing ligand-induced conformational switching may expose interior residues to solvent and cannot afford to be extremely rigid. Optimizing the energetic balance between stability and binding is challenging. The addition of five interdomain residues to rat and Paramecium calmodulin N-domain fragments (residues 1-75) increased their thermostability by 9 degrees C and lowered their calcium affinity by a factor of 4. This demonstrates that the flexible linker regulates functional properties as well as tethering the neighboring domains and that protein stability may be increased markedly by minor modifications of the C-terminus. The sensitivity of this domain to few and conservative variations in helices A and D (D2E, S17A, T70S and M71L) is demonstrated by the rat CaM fragments having lower stability and higher calcium affinity than fragments of the same length derived from Paramecium CaM.

Protein Structure, Tertiary

Calmodulin - genetics

Peptide Fragments - metabolism

Temperature

Calmodulin - metabolism

Calcium - metabolism

Models, Molecular

Protein Folding

Peptide Fragments - chemistry

Animals

Paramecium - metabolism

Protein Binding

Calmodulin - chemistry

Binding Sites

Peptide Fragments - genetics

Details

Title: Subtitle: An interdomain linker increases the thermostability and decreases the calcium affinity of the calmodulin N-domain
Creators: Brenda R Sorensen - Department of Biochemistry, University of Iowa College of Medicine, Iowa City, Iowa 52242-1109, USA
Laurel A Faga
Rainbo Hultman
Madeline A Shea
Resource Type: Journal article
Publication Details: Biochemistry (Easton), Vol.41(1), pp.15-20
Publisher: United States
DOI: 10.1021/bi011718+
PMID: 11771998
ISSN: 0006-2960
eISSN: 1520-4995
Grant note: R01 GM 5001 / NIGMS NIH HHS
Language: English
Date published: 01/08/2002
Academic Unit: Molecular Physiology and Biophysics; Psychiatry; Iowa Neuroscience Institute; Biochemistry and Molecular Biology
Record Identifier: 9984025272102771

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